Most dogs enjoy chewing on things although preferences vary as to the hardness of the substances favored. Some dogs like to chew on very hard materials such as cow bones, wood, nylon or polyurethane, others prefer softer chews such as rawhide, while still others favor freeze dried snacks. Some dogs, due to their age, may not be able to chew on the hard substances. Young dogs have insufficiently developed teeth, while old dogs may have diseased gums or may have lost some of their teeth.
In addition to the variety of chewing desires and needs of different dogs there is also the consideration that as one lowers the hardness of a material designated for chewing, the strength of a given chewing action may overcome the strength of the material, and the chew is susceptible to more rapid destruction. In that regard, efforts have been made to provide a chew toy that maintains the interest of an animal in a soft chewing medium, but which soft chew medium maintains itself intact in the chewing environment.
Along such lines, attention is directed to U.S. Pat. No. 6,474,268 entitled “Composite Chew Toy”. A synthetic chew toy is disclosed which is said to be formed of two different materials. The toy is described as requiring a rigid synthetic frame, supporting a softer chew portion. More specifically, a frame is shown (FIGS. 1-4) with what is described as four bulbous portions 210 at the ends thereof to simulate a bone shape. The frame is said to include a support shelf 220 having an inner wall 225 defining an opening 226 in the shape of an elongated oval. The frame 200 is also said to include a support wall 230 surrounding and perpendicular to the shelf 220 such that the shelf extends inward and perpendicular to an inner wall 231 of support wall 230. The '268 patent states that the rigidity of the frame provides structure, support and durability for the chew toy, and that the relatively softer chew portion can provide beneficial effects to a pet's teeth and gums, or provide greater chewing pleasure.
Attention is also directed to U.S. Pat. No. 5,263,436 entitled “Bone-Shaped Therapeutic Device”. A bone-shaped therapeutic chew toy device is disclosed for a dog consisting of material molded in a form having sharp conically shaped spikes distributed over its surface. The materials mentioned include polyethylene or a polyester or a polyamide having a durometer of 50-90.
The field of animal chews has also developed wherein a number of disclosures have occurred directed at those types of chews that may be characterized as edible based compositions. For example, attention is also directed to the following U.S. Patents, commonly owned by the assignee herein: U.S. Pat. No. 5,476,069 entitled “Molded Rawhide Chew Toy”; U.S. patent application Ser. No. 08/923,070 filed Sep. 3, 1997 entitled “Vegetable Based Dog Chew” now U.S. Pat. No. 6,093,427; U.S. patent application Ser. No. 08/738,423 filed Oct. 25, 1997 entitled “Edible Dog Chew” now U.S. Pat. No. 5,827,565; U.S. patent application Ser. No. 08/784,834 filed Jan. 17, 1997 entitled “Carrot-Based Dog Chew” now U.S. Pat. No. 5,941,197; U.S. patent application Ser. No. 09/114,872 filed Jul. 14, 1998 entitled “Heat Modifiable Edible Dog Chew” now U.S. Pat. No. 6,180,161; U.S. patent application Ser. No. 09/138,804 filed Aug. 21, 1998 entitled “Improved Edible Dog Chew” now U.S. Pat. No. 6,126,978; U.S. patent application Ser. No. 09/116,070 filed Jul. 15, 1998 entitled “Wheat & Casein Dow Chew With Modifiable Texture” now U.S. Pat. No. 6,110,521; U.S. patent application Ser. No. 09/116,555 filed Jul. 15, 1998 entitled “Heat Modifiable Peanut Dog Chew” now U.S. Pat. No. 6,093,441; U.S. patent application Ser. No. 09/227,767 filed Jan. 8, 1999 entitled “Method of Molding Edible Starch” now U.S. Pat. No. 6,159,516.
It is therefore an object of the present invention to provide an animal chew that offers chewing surfaces having different hardness values to satisfy different chewing preferences, and which provides a simpler, more economical, improved and longer-lasting design over the prior art.
It is therefore a related and more specific object of the present invention to provide an animal chew that offers chewing surfaces having different hardness values, wherein the edges of the softer surface are strategically concealed, at least in part, and wherein said edges may also be employed to secure the softer surface to the chew, thereby reducing the tendency to tear at an edge location, which therefore increases the life expectancy of the chew toy in the chewing environment.